1. Technical Field
The present disclosure generally relates to light emitting diode (LED) chips and method of manufacturing the same.
2. Description of Related Art
A light-emitting diode (LED) device is a lighting device made of semiconductor materials. The LED device has the advantages of small size, low power consumption, no radiation, mercury-free, long lifetime, fast response speed and high reliability. With the continuous progress of the recent technology, the application range thereof covers the information, communication, customer electronics, vehicle, lighting and traffic sign.
With reference to FIG. 3, a conventional LED device 9 includes a substrate 91, an epitaxial layer 92, a buffer layer 94, an N-type electrode 96, a P-type electrode 97 and a transparent conductive layer 98. The buffer layer 94, epitaxial layer 92 and transparent conductive layer 98 are disposed on the substrate 91 in sequence.
The epitaxial layer 92 includes an N-type semiconductor layer 921, a light-emitting layer 922 and a P-type semiconductor layer 923 in sequence. The N-type semiconductor layer 921 is disposed on the buffer layer 94. The light-emitting layer 922 is disposed on the N-type semiconductor layer 921. The P-type semiconductor layer 923 is disposed on the light-emitting layer 922. The N-type electrode 96 is electrically connected to the transparent conductive layer 98 via the epitaxial layer 92, and the P-type electrode 97 is directly electrically connected to the transparent conductive layer 98.
In general, the voltage and current of the LED device 9 usually have an exponential relationship. When the N-type electrode 96 and the P-type electrode 97 are applied with a voltage larger than the threshold voltage, the current through the LED device 9 is increased sharply. At the same time, the LED device 9 starts to light.
However, in the conventional structure of the LED device 9, the current distribution is non-uniform and is concentrated in the area A. This will cause the exceed current density in a localized area, which affects the lighting efficiency and results in overheat of the localized area. Moreover, the lifetime of the LED device 9 will be shortened.
Therefore, it is necessary to provide an LED package and method of manufacturing the same which can overcome the above shortcomings.